Angel Alvarez faces charges for his alleged role in the chaotic, deadly incident during a block party earlier this month.
His friends and family were vocal Thursday in support of his innocence.
But prosecutors are pushing hard to prove the 24-year-old is guilty of shooting at police during a wild gun fight that erupted in Harlem on August 8th.
It happened after Alvarez scuffled with another man over a 38 caliber revolver.
Luis Soto died at the scene when 46 bullets were blasted, including four from the 38 caliber revolver.
Four officers fired their guns.
While they did not testify at Thursday's hearing, three other officers did including Sgt. Phillip Tergos.
He said a cop standing over Alvarez's bullet riddled body at the scene told him that he had a gun, "That he definitely shot at me."
Officer Joe Green testified he saw a silver gun in Alvarez's hand as he lay bleeding on the ground and the emergency medical technician said Alaverez told her he'd gotten into a fight and then a shootout.
The Prosecutors goal Thursday was to prove there is enough evidence for their criminal case to go forward.
Mayor Michael Bloomberg says it's too soon to judge the police response.
"Somebody got killed, and the police who are putting their lives on the line to protect us were in the line of fire," Bloomberg said. "After that, I want to make sure that we followed all the procedure, and we will."
Alvarez has been charged with criminal possession of a weapon, but not attempted murder due to the complicated details of the night.
Police ballistics experts believe Alvarez shot Soto with Soto's gun, then turned on the police, prompting them to return fire.
Alvarez denies it, saying Soto had the gun and shot at police. The number of bullets in return fire by police has residents concerned.
"Why that many shots were fired, I don't understand at all," said Diana Boyde, of the 143rd Street Block Association. "I don't."
At the hearing, prosecutors will try to get Alvarez held in jail for 45 days while the grand jury investigates. If a judge rules against the prosecution, Alvarez will be out of jail by 5 p.m. Friday.